Check Engine Light - 97 C/K 5.0 L

My check engine light is flashing...upon checking the codes at Autozone two problems were listed:
1. Cylinder 7 misfire
2. O2 sensor

Unfortunately, the guy at autozone was in a hurry so he checked the codes and reset them and had to run. I did not have a chance to write them down. However, I decided to perform a tune-up ..plugs, cap, and rotor...now I am left with just:

1. Cylinder 7 misfire....

I did check the plug wires...they look good and they boots are still securely fastened.

Any ideas?
Does anyone know of a computer program and cable that can be installed on a PC to read OBDII codes?

Any help is appreciated.

The misfire code can set the O2 code. Check carefully the misfire, and make sure it is fixed before going for the O2 sensor. A misfire will cause extra O2 in the exhaust, confusing the system into thinking the O2 is the culprit. Ray

The misfire code can set the O2 code. Check carefully the misfire, and make sure it is fixed before going for the O2 sensor. A misfire will cause extra O2 in the exhaust, confusing the system into thinking the O2 is the culprit. Ray

You are correct. Upon performing a tune-up the 02 code went away.
Now I am left with the Cylinder 7 misfire code. Any ideas?

Have you tried running any injector cleaner through? The injector for cylinder 7 might be a little dirty.

Have you tried running any injector cleaner through? The injector for cylinder 7 might be a little dirty.

I did try injector cleaner and I just replaced the #7 plug wire and had the same results - cylinder 7 misfire.

The only thing I can think of except for what you have already replaced would be a leaking or broken pintle valve inside the injector. That would mean you would have to replace that one injector, but hopefully someone else might have a better idea of what it might be or what you could do.

Switch the plug wire around with one of similar length to a different cylinder and see if the misfire travels to the other cylinder.
After working at an auto shop/State Inspection Station for a while I have never seen a case where a misfire could not be remedied with a full tune-up. Whenever we see someone fail an inspection due to a misfire we always recommend spark plugs, spark plug wires, distributor cap and rotor replace and sometimes new PCV. Like I said, I have yet to see someone still have a misfire after a complete tune-up.